WO2005006003A1

WO2005006003A1 - Lsi test socket for bga

Info

Publication number: WO2005006003A1
Application number: PCT/JP2004/009832
Authority: WO
Inventors: Yasushi Kinoshita
Original assignee: Nec Corporation
Priority date: 2003-07-10
Filing date: 2004-07-09
Publication date: 2005-01-20
Also published as: US7477062B2; JP4775554B2; US20070018667A1; JPWO2005006003A1; US20060132160A1; US7129728B2

Abstract

An LSI test socket incorporating a POGO pin type decoupling capacitor for relaxing variation in the power supply and the GND potential when an LSI in a BGA package is tested. The LSI test socket comprises a printed board (102) incorporating a decoupling capacitor (113) corresponding to one or more power supply voltages, a POGO pin supporting housing section (104) being integrated with the overlying printed board (102), and a POGO pin (103) being inserted into a through hole formed by aligning a through hole (109) made through the printed board (102) and a hole (114) made through the POGO pin supporting housing section (104). When the LSI in the BGA package is tested, the printed board (102) is arranged on the upper surface side of the POGO pin supporting housing section (104) facing the BGA package or on the lower surface side of the POGO pin supporting housing section (104) facing a test board.

Description

Specification

LSI test socket for BGA

Technical field

The present invention relates to an LSI test socket used for testing an LSI incorporated in a BGA (Ball Grid Array) package, and more particularly to a BGA LSI test socket used for checking electrical parameters and the like. It relates to the structure of the socket.

Background art

[0002] For the purpose of more fully explaining the current state of the art relating to the present invention, reference should be made to all patents, patent applications, patent publications, scientific articles, and the like cited or specified in the present application. Incorporate all of those descriptions.

[0003] Conventionally, when performing a sorting test of an LSI incorporated in a BGA package having a high density and a large number of pins, it is necessary to prevent thermal and mechanical damage to solder balls of the BGA package. Test sockets (hereinafter referred to as LSI sockets) are used. LSI sockets used for this purpose are generally classified into two types: pogo pin type and sheet type.

[0004] Pogo pins are also referred to as spring pins or spring probe pins. Have been. A pogo pin type LSI socket using this pogo pin is provided with a coil-shaped spring structure together with a pin held by a resin housing, and by pressing up and down on the pin, an electrical connection is realized. You.

FIGS. 2A and 2B and FIGS. 3A and 3B are cross-sectional views showing the structure of a conventional BGA LSI socket using pogo pins. First, as shown in FIGS. 2A and 2B, this LSI socket is configured by combining a pogo pin 001 and a pogo pin support housing 005. That is, the structure of the LSI socket is such that the pogo pin 001 is inserted into the housing hole 010 from above or below the pogo pin support housing 005, which is a non-conductive material such as resin.

FIG. 2A shows a case where the pogo pin 001 is inserted into the housing hole 010 from below the pogo pin support housing 005 and fixed, and the stopper 006 is installed above the pogo pin support housing 005. The On the other hand, FIG. 2B shows a case in which it is inserted and fixed from above, and a stopper 006 is installed below the pogo pin supporting housing 005.

FIG. 3A shows a case where the LSI socket having the structure shown in FIG. 2A is set on the test board 009, and FIG. 7B shows a case where the LSI socket having the structure shown in FIG. 2B is set on the test board 009. In each case, the pogo pins 001 arranged corresponding to the positions of the solder balls 007 of the LSI enclosed in the BGA package are used to mechanically connect the wiring pad 008 on the test board 009 on which the LSI socket is mounted. The electrical connection is realized by pressing it from above. In general, this type of LSI socket has advantages such as low cost due to its simple structure, high mechanical strength, and the ability to be used repeatedly.

[0008] On the other hand, sheet-type LSI sockets use a conductive sheet, and there are two types of sheet, a metal wire-carrying type and a conductive rubber type. The sheet type has the advantage of being superior in high frequency characteristics because the pin length can be made shorter than the above-mentioned pogo pin type. However, there is a problem that the sheet which generates a large amount of dust due to scraping of the metal oxide is expensive and has a high running cost, and furthermore, there is a problem that the metal oxide adheres to the contact surface and the contact resistance increases.

[0009] Even when using any of these types of LSI sockets, extremely important problems have emerged with the recent high frequency operation and large power supply operation of LSIs. This is because the test frequency has increased with the significant improvement in the performance of the LSI to be tested, and the test conditions for the LSI incorporated in the BGA package have come to be performed in the high-frequency range on the order of GHz. As a result, an extremely large power supply current is generated, and the potential fluctuations of the LSI power supply and GND are apt to occur. In addition, in the test for sorting LSIs, the power required for LSI operation is supplied from a tester far from the LSI, so high-quality power can be supplied near the BGA package.

[0010] For this reason, if a capacitor cannot be placed in the vicinity of the BGA package to be tested, a power supply current will be generated due to the high frequency operation of the LSI, and the power supply and GND potential of the test board will fluctuate. However, it becomes difficult to ensure stable operation of the LSI incorporated in the BGA package. [0011] However, in addition to this, the conventional LSI socket has an essential problem that a decoupling capacitor for mitigating fluctuations in the power supply and GND potential fluctuations near the BGA package cannot be installed. is there. The reason is that the number of electrodes for LSI input / output signals, power supply and GND is increasing compared to the conventional one due to the improvement in integration, and the space between electrodes in the BGA package is narrowed due to the downsizing of the BGA package and the electrodes are dense. Gathering, and so on. Even if the test frequency is not so high, for example, in the case of an LSI having 512 parallel input / output lines, there is a problem that a very large instantaneous power supply current flows during simultaneous operation of IO.

[0012] As a means for alleviating the above-described fluctuations in the power supply and GND potentials, for example, in a sheet-type LSI socket, a plurality of electrodes on one side of a conductive sheet are connected by a conductive layer, and this conductive layer is brought into close contact with the sheet. A conductive sheet is used as a capacitor by connecting a plurality of electrodes on the other side with a conductive layer and making this conductive layer adhere to a sheet to form a GND layer (for example, see Patent Document 1). . As a result, a package-sized capacitor can be placed directly under the BGA package incorporating the LSI, and the effect of noise generated on the power supply and GND during high-frequency operation of the LSI can be reduced.

The above-mentioned conventional sheet-type LSI sockets are extremely difficult to realize due to their structure, and are expensive and lack the stability of repeated use, resulting in high running costs. Due to problems such as lack of contact, it cannot be used repeatedly at the mass production level. In addition, recent LSIs require a plurality of power supply voltages, and a large number of sheet voltages cannot be used.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-97991 (Page 3, FIG. 1-3)

Disclosure of the invention

Problems to be solved by the invention

[0013] Therefore, an object of the present invention is to solve a problem that occurs when testing an LSI encapsulated in a BGA package having an extremely large number of input / output signals, power supplies, and GND pins at a high frequency. It has a built-in decoupling capacitor that facilitates socket pin replacement, is low cost, and has a highly stable pogo pin structure, but also reduces power supply and GND potential fluctuations near the BGA package during testing. Pogo Pin Type LSI Soke Is to provide

Means for solving the problem

[0014] A first aspect of the gist of the present invention is that the first power supply plate coupled to the inner surface of the first through-hole and the second power supply plate coupled to the inner surface of the second through-hole are connected to a separator. A printed circuit board having at least one or more decoupling capacitors built therein via a printed circuit board, and the printed circuit board superimposed and integrated to form a first substrate at a position corresponding to the first and second through holes. A pogo-pin supporting housing portion in which at least one set of second housing holes is opened; the first and second through holes formed in the printed circuit board; and the first and second housing holes. At least one set of first and second pogo pins to be inserted into the through-holes that match the hole position of the BGA package. One end of the printed circuit board faces the BGA package when testing the LSI incorporated in the BGA package. do it The pogo pin support casing to provide a BGA for LSI test socket which is arranged in the end. The power supply plate is a plate that spreads in a plane that supplies power instead of a signal.It is made of foil or other material such as metal that has the function of an electrode of a decoupling capacitor. The potential to be applied includes not only the power supply voltage but also an intermediate potential, GND and a negative potential.

In the printed circuit board, a power supply layer corresponding to the first and second power supply plates and one GND layer are formed, and decoupling is performed using the capacitance between the power supply layer and the GND layer. Even if a capacitor is formed.

[0016] In the printed circuit board, a plating layer may be formed on the inner surface of the through hole into which the pogo pin for power supply and the pogo pin for GND other than the through hole into which the pogo pin for signal is inserted.

[0017] The pogo-pin supporting housing portion may be made of a non-conductive material, and the plating layer may not be formed on the inner surface of the housing hole.

[0018] The power supply layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for power supply is inserted, and the GND layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for GND is inserted. It is connected, and it may be.

[0019] A second aspect of the gist of the present invention is a first power supply plug coupled to an inner surface of a first through hole. A printed circuit board with a built-in decoupling capacitor, in which a power supply plate and a second power supply plate coupled to the inner surface of the second through hole are laminated via a separator, and this printed circuit board are superposed and integrated. A pogo pin support housing portion having first and second housing holes opened at positions corresponding to the first and second through holes, respectively, and the first and second housing holes formed in the print substrate; And a pogo pin inserted into a through-hole in which the hole positions of the first and second housing holes are matched with each other, and the pogo pin support is used when testing an LSI incorporated in a BGA package. Provided is a BGA LSI test socket in which one end of a housing portion faces a BGA package and the other end has the printed board.

In the printed circuit board, a power supply layer corresponding to the first and second power supply plates and one GND layer are formed, and decoupling is performed using the capacitance between the power supply layer and the GND layer. With the capacitor formed, it may be.

The printed circuit board has a plating layer formed on the inner surface of all through holes into which the signal pogo pins, the power pogo pins, and the GND pogo pins are inserted.

[0022] The pogo-pin supporting housing portion may be made of a non-conductive material, and a plating layer may not be formed on the inner surface of the housing hole.

The power supply layer is electrically connected to a plating layer on the inner surface of the through hole into which the pogo pin for power supply is inserted, and the GND layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for GND is inserted. On the other hand, the plating layer on the inner surface of the through hole into which the signal pogo pin is inserted may not be electrically connected to the power supply layer and the GND layer.

[0024] The pogo pins may be fixed to the through holes of the corresponding printed circuit boards by inserting the lower portions of the pogo pins and soldering via the plating layers.

The invention's effect

According to the present invention, by incorporating a decoupling capacitor in a BGA LSI socket, fluctuations in power supply potential of an LSI operating at a high frequency can be reduced, and a stable operation test can be performed. Can be. In addition, since the built-in part of the decoupling capacitor and the pogo-pin supporting housing part are separated into different parts, it is possible to realize a BGA LSI socket with good manufacturing stability and test stability. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)

The first embodiment of the present invention will be described below. FIG. 4 is an exploded longitudinal sectional view showing each component constituting the LSI socket for BGA of the present invention. FIG. 5 is a longitudinal sectional view showing a BGA LSI socket according to the first embodiment of the present invention.

As shown in FIG. 4, the LSI socket 101 of the present invention is composed of a printed circuit board 102, a pogo pin 103, and a pogo pin support casing 104. The printed circuit board 102 has a plurality of through-holes 109 into which a first power supply pin 105 and a second power supply pin 106, a GND pin 107, and a pogo pin 103 serving as a signal pin 108 having different voltage values to be applied are respectively inserted. The plating layer 116 is formed on the inner surface of all the through holes 109 except for the through hole 109 through which the signal pin 108 penetrates. In the printed circuit board 102, a first power supply layer 110, a second power supply layer 111, and a GND layer 112 are formed as a power supply plate, and each layer corresponds to an inner surface of a corresponding through hole 109 for each pogo pin. It is electrically connected to the plating layer 116.

[0029] A decoupling capacitor 113 is formed using the capacitance of a separator made of a dielectric or the like laminated between the power supply layers 110 and 111 and the GND layer 112. In FIGS. 4 and 5, two types of power pins are shown. The number of types of applied voltages is not limited. Further, the pogo pin supporting casing 104 is provided with a similar casing hole 114 at a position corresponding to the through hole 109 of the printed circuit board 102. A printed circuit board 102 is superimposed on the upper surface side of the pogo pin supporting casing 104, and is pressed or mechanically joined by using an adhesive material as shown in FIG. Note that no plating layer is formed on the inner surface of the housing hole 114.

Then, by inserting the pogo pins 103 into the holes where the positions of the through holes 109 and the housing holes 114 coincide with each other, the final structure as the LSI socket 101 is realized. The pogo pin 103 is inserted into the upper surface on which the printed circuit board 102 is installed, and is fixed by a stopper 115 formed below the housing hole 114 of the pogo pin support housing 104. Here, the first and second power supply layers 110 and 111 formed in the printed circuit board 102 and the GND layer Electrical connection between the 112 and the pogo pin 103 is realized by mechanical contact between the conductive material of the pogo pin 103 and the plating layer 116 on the inner surface of the through hole 109 in consideration of the ease of replacement of the socket pin.

When a test is performed using the thus configured LSI socket shown in FIG. 5, a solder ball (not shown) of a BGA package is brought into contact with the upper end of the pogo pin 103, and the lower end of the pogo pin 103 is shown in the drawing. The electrical contact is realized by the spring force of the pogo pins by contacting the pads of the test board.

[0032] With the above structure, the present embodiment incorporates a decoupling capacitor closer to the LSI side enclosed in a BGA package, while easily replacing socket pins and supporting multiple power supplies of recent LSIs. Since the printed circuit board is arranged, good characteristics can be obtained without being affected by the inductance component of the LSI socket pin.

(Second Embodiment)

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is an exploded longitudinal sectional view showing each component constituting the BGA LSI socket according to the second embodiment. FIG. 7 is a longitudinal sectional view showing a BGA LSI socket according to the second embodiment.

As shown in FIG. 6, the LSI socket 201 of the present invention is composed of four parts: a lower part 203A of pogo pins, a printed circuit board 202, an upper part 203B of pogo pins, and a pogo pin support housing part 204. . On the printed circuit board 202, a first power supply pin 205 and a second power supply pin 206, a GND pin 207, and a pogo pin 203 (consisting of 203A and 203B) for a signal pin 208 having different applied voltage values are respectively provided. A plurality of through holes 209 to be inserted are provided, and a plating layer 216 is formed on the inner surface of all the through holes 209. A first power supply layer 210, a second power supply layer 211, and a GND layer 212 are formed in the printed circuit board 202, and each of the layers is a plating layer on the inner surface of the corresponding through hole 209 for a pogo pin. 216 is electrically connected.

A decoupling capacitor 213 is formed using the capacitance of a separator made of a dielectric or the like laminated between the power supply layers 210 and 211 and the GND layer 212. Note that two types of power pins are shown in FIGS. 6 and 7. There is no limit to the number of types of applied voltage. What? In addition, the pogo pin support housing portion 204 is provided with a similar housing hole 214 at a position corresponding to the through hole 209 of the printed circuit board 202.

The lower part 203 A of the pogo pin is inserted into the through hole 209 of the printed board 202, and is fixed by soldering through the plating layer 216. Next, the spring and the upper part 203B of the pogo pin are fitted into the lower part 203A of the pogo pin fixed to the printed circuit board 202, and the pogo pin support housing part 204 is placed so as to cover it from above. At this time, the upper part 203B of the pogo pin is fixed by a stopper 215 provided above the housing hole 214.

Then, as shown in FIG. 7, the printed circuit board 202 is disposed below the pogo pin support housing 204 and fixed with screws or the like (not shown) in consideration of the exchangeability of the pogo pins. Integrated into the housing of 01.

[0038] With the above structure, in the present embodiment, a printed circuit board having a built-in decoupling capacitor is arranged in a direction away from the LSI side, so that the influence of the inductance component of the LSI socket pin occurs somewhat. In addition, the ease of replacement of the socket pins is sacrificed, but the electrical connection between the lower conductive part of the pogo pins and the decoupling capacitor is improved, making the LSI socket suitable for applications where large currents flow.

Industrial potential

The present invention is an LSI socket used for testing an LSI encapsulated in a BGA package at a high frequency. The adoption of a pogo pin structure allows the contact pins to be replaced, and at a low cost. Because it can be manufactured with a high degree of availability.

[0040] The present invention can be applied to any LSI socket used for testing an LSI enclosed in a BGA package at a high frequency, and can be applied to any LSI socket. There is no limitation at all.

Although the present invention has been described in connection with some preferred embodiments and examples, these embodiments and examples are merely illustrative of the invention and are not intended to be limiting. It is understood that this is not meant to be limiting. After reading this specification, it will be obvious to those skilled in the art that many changes and substitutions in terms of equivalent components and techniques will be readily apparent. Scope It is clear that this is true.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view showing a structure of a conventional pogo pin.

FIG. 2A is a vertical cross-sectional view showing a structure when a conventional pogo pin is inserted from below.

[FIG. 2B] is a longitudinal sectional view showing a structure when a conventional pogo pin is inserted from above.

FIG. 3A is a vertical sectional view showing a structure of a conventional LSI socket, and showing a structure when pogo pins are inserted from below.

FIG. 3B is a vertical sectional view showing a structure of a conventional LSI socket, and showing a structure when pogo pins are inserted from above.

FIG. 4 is an exploded longitudinal sectional view showing an LSI socket according to the first embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing an LSI socket according to the first embodiment of the present invention.

FIG. 6 is a structural exploded view showing an LSI socket according to a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing an LSI socket according to a second embodiment of the present invention.

Claims

The scope of the claims

[1] At least a decoupling capacitor in which a first power supply plate coupled to the inner surface of the first through hole and a second power supply plate coupled to the inner surface of the second through hole are laminated via a separator is provided. One or more built-in printed boards and the printed boards are overlapped and integrated to form at least one first and second housing holes at positions corresponding to the first and second through holes, respectively. A pair of pogo-pin supporting casings that are opened, and a through-hole in which the positions of the first and second through-holes and the first and second casing-holes formed in the printed circuit board are matched. At least one set of first and second pogo pins to be inserted into the BGA package, one end of the printed circuit board faces the BGA package and the other end supports The housing is LSI test socket for BGA.

[2] In the printed circuit board, a power layer corresponding to the first and second power plates and one GND layer are formed, and decoupling is performed by utilizing a capacitance between the power layer and the GND layer. 2. The BGA LSI test socket according to claim 1, wherein a ring capacitor is formed.

3. The BGA according to claim 1, wherein the printed circuit board has a plating layer formed on an inner surface of the through-hole other than the through-hole into which the signal pogo pin is inserted, and the through-hole into which the pogo pin for GND is inserted. For LSI test socket.

4. The BGA LSI test socket according to claim 1, wherein the pogo pin supporting housing portion is made of a non-conductive material, and no plating layer is formed on an inner surface of the housing hole.

[5] The power supply layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for power supply is inserted, and the GND layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for GND is inserted. 4. The BGA LSI test socket according to claim 2, which is electrically connected.

[6] A built-in decoupling capacitor in which a first power supply plate coupled to the inner surface of the first through-hole and a second power supply plate coupled to the inner surface of the second through-hole are laminated via a separator The printed circuit board and the printed circuit board are overlapped and integrated to form first and second positions respectively corresponding to the first and second through holes. A pogo pin supporting housing portion having a housing hole opened, and a through-hole in which the hole positions of the first and second through-holes and the first and second housing holes formed in the printed circuit board are matched. A pogo pin inserted into the hole, and at the time of testing an LSI incorporated in a BGA package, one end of the pogo pin support housing faces the BGA package and the print substrate is disposed at the other end. LSI test socket for BGA.

[7] In the printed circuit board, a power layer corresponding to the first and second power plates and one GND layer are formed, and decoupling is performed using the capacitance between the power layer and the GND layer. 7. The BGA LSI test socket according to claim 6, wherein a ring capacitor is formed.

8. The BGA LSI test socket according to claim 6, wherein the printed circuit board has a plating layer formed on the inner surfaces of all through holes into which the signal pogo pins, the power pogo pins, and the GND pogo pins are inserted.

9. The BGA LSI test socket according to claim 6, wherein the pogo pin supporting housing portion is made of a non-conductive material, and a plating layer is formed on an inner surface of the housing hole.

[10] The power supply layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for power supply is inserted, and the GND layer is electrically connected to the plating layer on the inner surface of the through hole into which the pogo pin for GND is inserted. 9. The BGA LSI test socket according to claim 7 or 8, wherein the plating layer inside the through hole into which the signal pogo pin is inserted is not electrically connected to the power supply layer and the GND layer.

11. The BGA LSI test socket according to claim 8, wherein each of the pogo pins is inserted into a corresponding through hole of a printed circuit board by inserting a lower portion of the pogo pin and soldering the pogo pin via a plating layer.